Multi-chamber rotary vane compressor



y 7; 1968 F. o. BELLMER MULTI-CHAMBER ROTARY VANE COMPRESSOR 5 Sheets-Sheet 1 Filed March 2, 1966 INVENTOR. .1 N.

FIG.6

May 7, 1968 F. o. BELLMER MULTI-CHAMBER ROTARY VANE COMPRESSOR 2 v e e h S S t .e e h s 5 6 K 2 I O W C r a M d e.\ 6 1 2 FRIEDRICH o. BELLM ER INVENTOR.

fim N M FIGJS May 7, 1968 Filed March 2, 1966 F. O. BELLMER MULTI-CHAMBER ROTARY VANE COMPRESSOR I5 Sheets-Sheet 3 FIG.I8

FRIEDRICH O. BELLMER INVENTOR.

Unit

ABSTRACT OF THE DISCLOSURE A rotary sliding vane compressor having multiple compression chambers circumferentially spaced within the rotor housing with groups of chambers serially connected to provide pressure staging.

In general, this invention relates to a new and improved multi-chamber rotary vane compressor and more particularly to a multi-chamber rotary compressor which can achieve single or plural stage compression with only a single rotor and is sufi'iciently versatile that while operating as a single stage compressor, it can be unloaded in a simple and easy manner.

The conventional single acting one chamber rotary vane compressor runs unbalanced and is restricted therefore to low speeds. A two or three stage compressor of this kind has two or three separate rotors in separate housings which cause enormous bearing and machining problems and higher weight and space requirements, resulting in very high production costs.

Further, in prior art two or more stage compressors, the vane wear is higher in the high pressure stages because of high load and high temperature. Thus, in these high pressure stages, the lifetime of the vanes is substantially less than that of those in the low pressure stages and, accordingly, vanes in one portion of the compressor must be changed while others, in the low pressure stages, need not be changed which thus requires frequent servicing of the compressor.

The present invention contemplates a multi-chamber rotary vane compressor in which the rotor is perfectly balanced when running as a single stage compressor and, thus, the only forces thereon are in torque, and there is no side thrust as is found in conventional single-chamber rotary vane compressors. The multi-cham-ber compressor of the present invention includes the well known advantages of compactness while additionally providing flexibility as the compressor can be easily adapted for compounding or conversion from a single stage to a two, three, or more stage compressor. Even when utilized as a plural stage compressor, there is equal wear on all of the vanes Whether they are running in high or low pressure stages. This increases the lifetime of the vanes. Overheating of the vanes is also eliminated as the vanes are continuously passed through the high pressure stage into the low pressure stages of the compressor. Because of the flexibility of the compressor of the present invention, the cost thereof has been substantially reduced as only a single rotor is necessary to provide apparatus which can operate as a single, double, or three-stage compressor with the possibility of unloading certain of the chambers during single stage operation to achieve even further flexibility.

Accordingly, it is the general object of this invention States Patent to provide a new and improved multi-chamber rotary vane compressor.

Another object of this invention is the provision of a new, more versatile, and less expensive multi-chamber rotary vane compressor which can beconverted from single stage compression to two or more stages of compression.

Still another object of this invention is the provision of a new and better multi-chamber rotary vane compressor in which the vanes will have equal wear thereon whether the compressor is operating as a single stage or multi-stage unit.

A further object of this invention is the provision of a new and better rotary vane compressor which can be unloaded in a simple and easy manner and, additionally, can be converted from a single stage to a plural stage operation.

Other objects will appear hereinafter.

For the purpose of illustrating the invention, there are shown in the drawings forms which are presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.

FIGURE 1 is an elevational view of a multi-chamber single stage compressor built in accordance with the principles of the present invention.

FIGURE 2 is a longitudinal sectional view of the compressor of FIGURE 1 taken through the compressor portion of the unit shown in FIGURE 1.

FIGURE 3 is a cross-sectional view of the compressor of FIGURE 1 taken along lines 3--3.

FIGURE 4 is a cross-sectional view of the apparatus of FIGURE 1 taken along lines 4-4.

FIGURE 5 is a cross-sectional view of the apparatus of FIGURE 1 taken along lines 5-5.

FIGURE 6 is a schematic diagram of the single stage compressor of FIGURES 1-5.

FIGURE 7 is a cross-sectional view similar to FIG- URE 5 of a modified compressor built in accordance with the principles of the present invention.

FIGURE 8 is a longitudinal elevational view of a multi-chamber two stage compressor built in accordance with the principles of the present invention.

FIGURE 9 is a longitudinal section through the second stage of the compressor of FIGURE 8.

FIGURE 10 is a cross-sectional View taken along lines 1010 of FIGURE 8.

FIGURE 11 is a cross-sectional view taken along lines 1111 of FIGURE 8.

FIGURE 12 is a cross-sectional view taken along lines 1212 of FIGURE 8.

FIGURE 13 is an enlarged sectional view of the closing means shown in FIGURE 12.

FIGURE 14 is a cross-sectional view similar to FIG- URE 12 of a modified form of the end cover for a two stage compressor similar to a two stage compressor shown in FIGURES 8l3.

FIGURE 15 is a schematic diagram of the compressor of FIGURES 8-l3.

FIGURE 16 is a cross-sectional view of a three stage compressor built in accordance with the principles of the present invention.

FIGURE 17 is a schematic showing of the compressor of FIGURE 16.

FIGURE 18 is a schematic showing of a modified form of the compressor of FIGURES 16 and 17.

FIGURE 19 is a schematic showing of a revised form of the compressor of FIGURES 16, 17 and 18.

In FIGURE 1, there is shown a motor driven multichamber single stage compressor built in accordance with the principles of the present invention and generally designated by the numeral 20. The motor driven compressor 20 includes a motor casing 22 and a compressor casing 24 within which are mounted respectively, the motor (not shown) and the compressor 26 driven thereby.

The motor casing 22 has a fluid inlet 28 through which the fluid to be compressed is passed. The inlet 28 normally is utilized to pass therethrough refrigerant which will cool the motor within the casing 22 and, thereafter, be compressed within the compressor 26. The motor drives a shaft 30 which has mounted thereon a rot-or 32 which forms the single rotor for the compressor 26. The rotor 32. is mounted on bearings 34 and 36, which. bearings are respectively supported at the ends of the rotor 32 by an inwardly extending extension of the casing 24 and an end cover 38 forming a part of the casing 24. The end cover 38 has a discharge opening 40 out of which the compressed refrigerant passes after having been compressed within the compressor 26. The casing 24 has fixed therewithin a rotor housing 42 contiguous with the inner surface of the casing 24 and having its end closest to the motor covered by a suitable inlet plate 44. The inlet plate 44 has three inlet openings 46, 48, and as best shown in FIGURE 4 which inlet openings are aligned with axially extending inlet passageways 52, 54, and 56 respectively. The inlet passages 52, 54, and 56 are formed in the rotor housing 42. The interior surface of the rotor housing 42 forms a cavity within which the rotor 32 can rotate with its surface touching three axially extending parallel lines on the interior of the rotor housing 42 and having arcuate recesses on the interior of the rotor housing 42 so that there will be defined between the surfac of the rotor 32 and the interior of the rotor housing 42 three compression chambers 58, 60, and 62 respectively positioned equidistant from one another. Each of the inlet passageways 52, 54 and 56 is in communication with one end of its associated respective chamber 58, 60, and 62 through slots 64 formed in the rotor housing 42.

The rotor 32 has twelve vanes 66 positioned within radial slots 68 equally spaced about the circumference of the rotor 32. Vanes 66 and their associated slots 68 extend the length of the rotor 32.

At the end of each chamber 58 and and 62 opposite from the inlets 52, 54, and 56 there are positioned outlet passageways 70, 72, and 74 which communicate with the interior of the rotor housing 42 through slots 76, 78, and 80. The longitudinally extending passageways 70, 72, and 74 are all in communication with a continuous passageway 82 in the end plate 38 which communicates with discharge opening 40.

The compressor housing 24 has a suction inlet 84 therein adjacent the inlet plate 44, which suction inlet is in communication with a passageway 86 which passageway connects the inlet openings 46, 4S, and 59.

The operation of the compressor 24 can best be understood with reference to FIGURE 6 in which the compressor is shown schematically.

Refrigerant fluid enters suction inlet 84, and is distributed through the passageway 86 and inlet plate openings 46, 48, and 58 into inlet passageways 52, 54, and 56 respectively. Thence, the refrigerant passes through the slots 4 into the compressor chambers 58, 60, and 62.

Within the chambers 58, 66, and 62, adjacent vanes 66 in cooperation with the rotor 32 and rotor housing 42 will form fluid transfer pockets to compress the refrigerant fluid in the usual manner of a rotary vane compressor, said vanes being forced outwardly by centrifugal force to conform to the inner surface of the rotor housing 42. The fluid transfer pockets approach their maximum volumetric capacity adjacent inlet slots 62 and approach their minimum volumetric capacity adjacent outlet slots 76, 78, and 80. The compressed refrigerant is forced through the slots 76, 78, and into the discharge passageways 70, 72, and 74 respectively. Thence, the now compressed fluid will pass through the outlet passageway 82 to the discharge outlet 40. It will be noted that each one of the chambers 58, 60, and 62 will be reacting in the same manner, at the same time, so that there will be no rotor imbalance and no side thrust on the bearings 34 and 36.

In FIGURE 7, there is shown a modified form of the compressor 26 end cover in a cross-sectional view similar to FIGURE 5. This compressor 26' is modified by the addition of a second inlet opening 88 into the inlet passageway 50 (not shown). The inlet opening 88 is connected to an extension 90 of the passageway 82' which extension 90 connects end cover opening 88 with passageway 72'. However, between passageway 72' and second inlet opening 88, in extension 90, there is provided a plug 92 which eflectively closes the passageway 90. However, the plug 92 can be withdrawn for purposes which will be shown hereinafter with respect to FIGURES 9-13. In the passageway 82 between outlet passageway 70 and discharge opening 40, there is provided a position 94 for a second plug 98. It will be understood that the plug 98 fitting into position 94 is in a withdrawn position and, thus, the compressor 26' shown in FIGURE 7 would be exactly like the compressor shown in FIGURES l-6 in operation.

In FIGURE 8, there is shown the multi-cham-ber compressor 26' of FIGURE 7 connected up as a two stage compressor.

Compressor 26 is like the compressor 26' discussed in FIGURE 7 except that the plug 92 has been screwed out to leave an open plug position 96, whereas the plug positioned 94 has been filled by screwing the plug 98 into place. Further, the plate 44 has been modified by eliminating the inlet opening 50 to the inlet passageway 56. This has produced a new inlet plate 44' as shown in FIGURE 11 having only two openings 46' and 48' which operated in a manner exactly like the inlets 46 and 48 described with respect to FIGURE 4. The end cover 38 is exactly like the end cover described in FIGURE 7.

The operation of the two stage compressor shown in FIGURES 8-13 is best shown in FIGURE 15 which describes the operation of a compressor 26'. Thus, refrigerant fluid enters the suction inlet 84, and is distributed through the passageway 86 to the openings 46' and 48' in the plate 44'. The plate 44' prevents fluid from entering the compression chamber 62. from the passageway 86, but rather, the fluid enters the passageways 52 and 54 into the compression chambers 58 and 60. After compression within the chambers 58 and 60, the fluid is forced out of the openings 70 and 72 into the passageway 82. The plug 98 prevents fluid leaving the passageways 70 and 72 from passing directly out the compressor outlet 40, but, instead, this fluid passes through the extension 92 into the inlet 88 of compressor chamber 62 which will then further compress the fluid before it is passed out of the compression chamber 62 through outlet 74 to the compressor outlet 40. Accordingly, with a single rotor, it has been possible to achieve two stage compression of the refrigerant fluid while maintaining a balanced rotor.

Still further, it should be noted that the vanes 66, during their travel through the compression chambers 58, 60 and 62 will be equally worn as they will pass through both the high pressure compression stage 62 as well as the low pressure compression stages 58 and 60 and, accordingly, there will be even wear thereon.

This transformation from a three chamber single stage compressor to a three chamber two stage compressor has been achieved by merely varying the positions of the plugs 92 and 98 and replacing the suction inlet plate 44 with the plate 44. It will be understood that other types of valve closing of inlet 56 could have been utilized in accordance with the principles of the present invention such as by inserting a plug into the inlet 56 rather than re placement of the plate 44.

In FIGURE 14, there is shown a modified form of the end cover 38 shown in FIGURE 12 in which a more permanent form of the two stage compressor is shown in that the plugs 92 and 96 have been removed and the passageway opened and that portion of the passageway 82 which extended from outlet 70 to the outlet 40 has been closed. Thus, this will operate in exactly the same way as the end cover shown in FIGURE 12.

In FIGURE 16, there is shown another form of the present invention generally designated by the numeral 100. The compressor 100 is a six chamber, three stage unit having a single rotor 102, cylindrical in cross-section. The rotor 102 has vanes 104 adapted to be thrown outwardly by centifugal force against the inner surface of a rotor housing 106. The rotor housing 106 has a longitudinally extending cavity therein within which the rotor 102 rotates, which rotor 102 contacts the rotor housing within the cavity along six equally spaced parallel lines to define between the parallel lines six crescent shape chambers 108, 110, 112, 114, 116, and 118. The chambers 103418 each have respective inlet passageways 120, 122, 124, 126, 28, and 130. Gases are exhausted from the chambers 108- 118 through exhaust ports 132 134, 136, 138, 140, and 142 respectively.

Exhaust ports 134, 136, and 138 are connected through a common conduit 144 to the common conduit 146 supplying inlet ports 128 and 130. Outlet ports 1 10 and 142 are connected through a single passageway 148 to the inlet passageway 150 for inlet 120.

Inlet ports 122, 124, 126 are supplied through a common conduit 152 from a suction inlet 154. Thus, as best shown in FIGURE 17, refrigerant gas enters the suction inlet 154, passes through the common conduit 152 into the inlet ports 122, 124, and 126 respectively and thence to the compression chambers 110, 112, and 14 respectively. After compression in the chambers 110, 112, 114, the refrigerant fluid, now compressed, passes through the outlet ports 134, 136 and 138 through the common outlet conduit 144 to the common inlet conduit 146 for inlet ports 128, and 130. Inlet ports 128 and supply the one stage compressed refrigerant fluid to chambers 116 and 118 wherein the refrigerant fluid is further compressed and thence transmitted through outlet conduits and 142 to the common outlet passageway 148 into the inlet passageway connected to the inlet ports 120 for final third stage compression chamber 108. In the third stage compression chamber 108, the refrigerant fluid is further compressed and then forced out of outlet conduit 132. Thus, the refrigerant fluid passing out of outlet conduit 132 has gone through three stages of compression. It will be understood that the refrigerant fluid will be compressed in each stage, thus requiring less volume and, accordingly, one less chamber for each stage of compression. Further, it will be noted that the vanes 10- will pass through the low pressure, medium pressure, and high pressure stages during each rotation of the rotor 102 and, accordingly, there will be equal wear on all of the vanes thus cutting down on unnecessary breakdowns of the compressor 100. It will be understood that in accordance with the teachings of the present invention, the compressor 100 could have been operated as a single stage compressor as shown in FIGURE 19 with all of the inlets 120-123 directly connected to the inlet port 154 and all of the outlet ports being connected together.

Similarly, the compressor 100 can be operated as a two stage compressor as shown in FIGURE 18 wherein the compressor 100 is shown having four inlets 122, 124, 126', and 128 connected to the common inlet 154' to feed chambers 110, 112', 114', and 116 respectively. The output ports 134', 136, 138 and 14-0 of chambers 110'116 are connected to the inlet ports 130' and 120' of chambers 118' and 108 respectively. The outlet conduits 142' and 132' of chambers 118 and 108' respectively are connected together to form an outlet which will supply refrigerant fluid which has passed through two compression stages.

In FIGURE 19 there are shown in the six compression chambers 108-118 with their inlets connected to the common suction inlet 154" through respective valves 160, 162, 164, 166, 168, and 170. The outlets of each of the compression chambers 108-118 is connected a common outlet conduit 172. It will be understood that the compressor shown in FIGURE 19 can be unloaded in a balanced manner by closing one or more of the valves 170. For example, if two of the valves 160 and 162 are closed, the compressor will be 67% loaded, with three valves closed the compressor will be 50% loaded, with four valves closed the compressor will be 33% loaded, etc.

Thus, the basic compressors shown in FIGURES 16- 19 can be operated as a single stage compressor with six chambers, capable of being unloaded to a varying extent, as noted in FIGURE 19; as a two stage compressor as shown in FIGURE 18; or as a three stage compressor as shown in FIGURES l6 and 17. All of this is achieved with a balanced rotor and with even wear of the vanes.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims rather than to the foregoing specification as indicating the scope of the invention.

I claim:

1. A multiple stage rotary compressor of the sliding vane type including:

(a) a rotor housing having a non-cylindrical cavity therein defined by an inner wall of the housing;

(b) a cylindrical rotor mounted in the housing for rotation in said cavity;

(c) said rotor and said housing inner wall defining a plurality of chambers equally spaced about said inner wall at one axial position along the rotor with each chamber being crescent-shaped and congruent to every other chamber, each chamber having an inlet port and an outlet port spaced therefrom;

(d) vane elements extending radially outwardly from said rotor and engaging said inner wall to form fluid transfer pockets between adjacent vane members;

(e) said vane elements being radially movable whereby the volumetric capacity of said fluid transfer pockets approaches a maximum as said fluid transfer pockets communicate with said inlet ports and approaches a minimum as said fluid transfer pockets communicate with said outlet ports;

(f) means for rotating said rotor to cause the capacity of said pockets to decrease while communicating with said outlet ports;

(g) interconnection passageways connecting the outlet ports of a first group of the chambers forming a first stage to the inlet ports of a second group of chambers forming a second stage;

(h) compressor outlet means connected to the outlet ports of said second group of chambers, and

(i) suction inlet means connected to the inlet ports of said first group of chambers.

2. The rotary compressor of the sliding vane type of claim 1 including:

(j) selective connection means operative with said interconnection passageways, compressor outlet means, and suction inlet means to change the operation of said interconnection passageways and to selectively connect certain of the outlet ports of certain chambers to certain of the inlet ports of other chambers or change the operation of said interconnection passageways to connect all of the inlet ports to the suction inlet means and all of the outlet ports to said compressor outlet means.

3. The rotary compressor of the sliding vane type of claim 2 wherein said interconnection passageways are formed in said rotary housing to connect a plurality of said outlet ports to certain of said inlet ports and said compressor outlet means, said selective connection means including valve members for closing off certain portions of said interconnection passageways to effect connection of certain outlet ports to particular inlet ports and to conmeet the remaining outlet ports to said compressor outlet means.

4. The rotary compressor of the sliding vane type of claim 1 wherein said rotor and said housing inner wall define 3 It chambers equally spaced about said inner wall, where n is a whole number, said interconnection passageways first group of chambers comprising 2 n chambers.

5. The rotary compressor of the sliding vane type of claim 4 wherein n is 2.

6. The rotary compressor of the sliding vane type of claim 1 wherein said one group of chambers is greater in number than said second group of chambers.

7. The rotary compressor of the sliding vane type of claim 6 wherein said interconnection passageways are further operative to connect the outlet ports of said second group of chambers to inlet ports of a third group of chambers, said third group of chambers being less in number than said second group of chambers said compressor outlet means including said third group of chambers whereby a further stage of compression can be achieved by said rotary compressor.

8. The rotary compressor of the sliding vane type of claim 7 including selective connection means for effecting a change in said interconnection passageways to connect all of said inlet ports to said suction inlet means and all of said outlet ports to said compressor outlet means, to connect the outlet ports of certain chambers to the inlet ports of other chambers with the remaining outlet ports being conneced to the compressor outlet means and the remaining inlet ports connected to the suction inlet means, or to leave the interconnection passageways unelfected by said selective connection means.

9. The rotary compressor of the sliding vane type of claim 8 wherein said selective connection means is further operative to connect all of the outlet ports to the compressor outlet means and to connect only certain of the inlet ports to the suction inlet means to thereby unload the compressor.

10. A compressor comprising:

(a) a motor;

(b) a casing within which said motor is positioned;

(c) a partition within said casing defining a motor compartment and a compressor compartment, said motor being positioned within said motor compartment;

(d) a compressor rotor driven by said motor mounted within said compressor compartment, said rotor being cylindrical in shape;

(e) a rotor housing within said compressor compartment, said rotor housing having a non-cylindrical cavity therein defined by an inner wall of the rotor housing;

(f) said cylindrical rotor being mounted for rotation within said cavity and defining with said housing inner wall a plurality of individual compression chambers equally spaced about said inner wall with each individual compression chamber being congruent to every other compression chamber and each compression chamber having an inlet port and an outlet port spaced therefrom,

(g) longitudinally extending parallel vane elements extending radially outwardly from said rotor in slots formed in the surface of said rotor, said vanes being operative to engage by reason of centrifugal force said inner wall to form fluid transfer pockets between adjacent vane members;

(h) said vane elements being radially movable within said slots whereby the volumetric capacity of said fluid transfer pockets approaches a maximum as said fluid transfer pockets communicate with said inlet ports and approaches a minimum as said fluid transfer pockets communicate with said outlet ports;

(i) passageways interconnecting the outlet ports of a first group of individual compression chambers to the inlet ports of a second group of individual compression chambers, said first group being greater in number than said second group;

(j) compressor outlet means connected to the outlet ports of said second group of individual compression chambers; and

(k) compressor inlet means connected to the inlet ports of said first group of individual compression chambers.

11. The apparatus of claim 10 wherein said interconnection passageways are further operative to connect the outlet ports of said second group of individual compression chambers to the inlet ports of a third group of individual compression chambers, the outlet ports of said third group of individual compression chambers being connected to said compressor outlet means, said third group of individual compression chambers being less in number than said second group of individual compression chambers.

12. The apparatus of claim 11 including selective connection means for varying said interconnection passageways to arrange a fourth and fifth group of individual compression chambers formed from the chambers forming said first and second and third groups, said fourth group outlet ports being connected to the inlet ports of said fifth group, said fifth group outlet ports being connected to said compressor outlet means and said fourth group inlet ports being connected to said compressor inlet means, said fourth group being greater in number than said fifth group.

13. The apparatus of claim 12 wherein said selective connection means is operative to connect all of said individual compression chamber outlet ports to said compressor outlet means and all of said individual compression chamber inlet ports to said compressor inlet means and further including valve means for disconnecting certain of said inlet ports from said compressor inlet means.

14. A multiple stage rotary sliding vane compressor comprising:

(a) a rotor housing having a non-circular cylindrical cavity therein;

(b) a circular cylindrical rotor mounted in the housing for rotation in the cavity;

(c) the rotor and the housing inner wall defining a plurality of circumferentially spaced crescent-shaped chambers at one axial position along the rotor, each chamber having an inlet port and an outlet port spaced therefrom;

(d) vane elements extending radially outwardly from the rotor and engaging the inner Wall of the housing to form fluid transfer pockets between adjacent vane members;

(e) vane elements being radially movable whereby the volumetric capacity of the fluid transfer pockets approaches a maximum as the transfer pockets communicate with the inlet ports and approaches a minimum as the fluid transfer pockets communicate with the outlet ports;

(f) means for rotating the rotor to cause the capacity of the pockets to decrease while communicating with the outlet ports;

(g) means for connecting the inlets of the first group of the chambers in parallel to a common inlet to form a first compression stage;

(h) means for connecting the inlets of a second group of the chambers in parallel to the outlets of the first group of chambers to form a second compression stage; and

(1) means for connecting the outlets of the second group of chambers in parallel to a comon outlet.

References Cited UNITED STATES PATENTS Mercier et a1. 230159 Mercier et al. 230-159 Adams et a1. 103136 Adams et a1 103-436 Ostwald 103-436 Kroeger 230152 FRED C. MATTERN, JR., Primary Examiner.

WILBUR J. GOODLIN, Examiner. 

